Install the current versions of MSYS and MinGW from
http://www.mingw.org/. You can find detailed installation
instructions in the download section and the FAQ.
Download
the MinGW development library of SDL 1.2.x
(SDL-devel-1.2.x-mingw32.tar.gz) from
http://www.libsdl.org. Unpack it in a temporary place, and
unpack the archive i386-mingw32msvc.tar.gz in the MinGW tool
directory. Edit the sdl-config script so that it gives the
correct SDL directory when invoked.
Extract the current version of QEMU.
Start the MSYS shell (file msys.bat).
Change to the QEMU directory. Launch ./configure and
make. If you have problems using SDL, verify that
sdl-config can be launched from the MSYS command line.
You can install QEMU in Program Files/Qemu by typing
make install. Don't forget to copy SDL.dll in
Program Files/Qemu.